Systems and methods of registration for image guided surgery

ABSTRACT

A system includes a manipulator and a processing unit. The processing unit is configured to receive, from a position sensor system, a collected set of spatial information for a distal portion of a medical instrument collected at locations within anatomic passageways as a rigid instrument body is moved in an insertion or retraction direction. The processing unit is further configured to receive, from a position measuring device, a set of position information related to a position of the rigid instrument body when the distal portion is at the locations. The processing unit is further configured to, based at least in part on the set of position information, determine a subset of the set of spatial information relative to the environment coordinate space and, based on the subset of spatial information, determine an initial transform for registering the set of spatial information with anatomical model information in a model coordinate space.

RELATED APPLICATIONS

This patent application is a continuation of U.S. patent applicationSer. No. 15/574,545, filed Nov. 16, 2017, which is the U.S. nationalphase of International Application No. PCT/US2016/033596, filed May 20,2016, which designated the U.S. and claims priority to and the benefitof the filing date of U.S. Provisional Patent Application No.62/165,249, entitled “SYSTEMS AND METHODS OF REGISTRATION FOR IMAGEGUIDED SURGERY,” filed May 22, 2015, both of which are incorporated byreference herein in their entireties.

FIELD

The present disclosure is directed to systems and methods for conductingan image guided procedure, and more particularly to systems and methodsfor displaying pathology data for tissue sampled during an image guidedprocedure.

BACKGROUND

Minimally invasive medical techniques are intended to reduce the amountof tissue that is damaged during medical procedures, thereby reducingpatient recovery time, discomfort, and deleterious side effects. Suchminimally invasive techniques may be performed through natural orificesin a patient anatomy or through one or more surgical incisions. Throughthese natural orifices or incisions clinicians may insert minimallyinvasive medical instruments (including surgical, diagnostic,therapeutic, or biopsy instruments) to reach a target tissue location.To assist with reaching the target tissue location, the location andmovement of the medical instruments may be correlated with pre-operativeor intra-operative images of the patient anatomy. With the image-guidedinstruments correlated to the images, the instruments may navigatenatural or surgically created passageways in anatomical systems such asthe lungs, the colon, the intestines, the kidneys, the heart, thecirculatory system, or the like. Traditional instrument trackingsystems, including electromagnetic sensing tracking systems, may disturbthe clinical environment or workflow. Systems and methods for performingimage guided surgery with minimal clinical disturbances are needed.

SUMMARY

The embodiments of the invention are summarized by the claims thatfollow the description.

In one embodiment, a method performed by a computing system comprisesreceiving a collected set of spatial information for a distal portion ofan instrument at a plurality of locations within a set of anatomicpassageways and receiving a set of position information for a referenceportion of the instrument when the distal portion of the instrument isat each of the plurality of locations. The method also comprisesdetermining a reference set of spatial information for the distalportion of the instrument based on the collected set of spatialinformation and the set of position information for the referenceportion of the instrument and registering the reference set of spatialinformation with a set of anatomical model information.

In another embodiment, a method comprises collecting a set of spatialinformation from an optical fiber shape sensor extending within amedical instrument coupled to a teleoperational assembly when a distalportion of the instrument is at a plurality of locations within a set ofanatomic passageways. The method also comprises receiving a set ofposition information from a position sensor for a drive system of theteleoperational assembly when the distal portion of the instrument is atthe plurality of locations within the set of anatomic passageways anddetermining a set of proximal position data for a proximal portion ofthe instrument when the distal portion of the instrument is at theplurality of locations. The set of proximal position data is determinedbased upon the position information from the position sensor andcalibration information between the position sensor and a fixedinsertion track along which the proximal portion of the instrumentmoves. The method also comprises determining a reference set of spatialinformation for the distal portion of the instrument based on thecollected set of spatial information and the set of proximal positiondata and registering the reference set of spatial information with a setof anatomical model information.

In another embodiment, a system comprises a teleoperational assemblyincluding an operator control system and a manipulator configured forteleoperation by the operator control system. The manipulator isconfigured to control movement of a medical instrument in a surgicalenvironment. The system also comprises a processing unit including oneor more processors. The processing unit is configured to receive acollected set of spatial information for a distal portion of the medicalinstrument at a plurality of locations within a set of anatomicpassageways and receive a set of position information for a referenceportion of the medical instrument when the distal portion of theinstrument is at each of the plurality of locations. The processing unitis also configured to determine a reference set of spatial informationfor the distal portion of the medical instrument based on the collectedset of spatial information and the set of position information for thereference portion of the medical instrument and register the referenceset of spatial information with a set of anatomical model information.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory innature and are intended to provide an understanding of the presentdisclosure without limiting the scope of the present disclosure. In thatregard, additional aspects, features, and advantages of the presentdisclosure will be apparent to one skilled in the art from the followingdetailed description.

BRIEF DESCRIPTIONS OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isemphasized that, in accordance with the standard practice in theindustry, various features are not drawn to scale. In fact, thedimensions of the various features may be arbitrarily increased orreduced for clarity of discussion. In addition, the present disclosuremay repeat reference numerals and/or letters in the various examples.This repetition is for the purpose of simplicity and clarity and doesnot in itself dictate a relationship between the various embodimentsand/or configurations discussed.

FIG. 1 is a teleoperated medical system, in accordance with embodimentsof the present disclosure.

FIG. 2A illustrates a medical instrument system utilizing aspects of thepresent disclosure.

FIG. 2B illustrates a distal end of the medical instrument system ofFIG. 2 with an extended medical tool.

FIG. 3 illustrates the distal end of the medical instrument system ofFIG. 2 positioned within a human lung.

FIG. 4 is a flowchart illustrating a method used to provide guidance inan image guided surgical procedure according to an embodiment of thepresent disclosure.

FIGS. 5A, 5B, and 5C illustrate steps in a segmentation process thatgenerates a model of a patient anatomy for registration according to anembodiment of the present disclosure.

FIGS. 6 and 7 are side views of a surgical coordinate space including amedical instrument mounted on an insertion assembly.

FIG. 8 illustrates flowchart illustration a portion of an image guidedsurgical procedure according to an embodiment of the present disclosure.

FIGS. 9 and 10 illustrate a registration technique according to anembodiment of the present disclosure.

FIG. 11 illustrates a seeding process of an image guided surgicalprocedure according to an embodiment of the present disclosure.

FIG. 12 illustrates a registration display stage of a registrationtechnique according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description of the aspects of the invention,numerous specific details are set forth in order to provide a thoroughunderstanding of the disclosed embodiments. However, it will be obviousto one skilled in the art that the embodiments of this disclosure may bepracticed without these specific details. In other instances well knownmethods, procedures, components, and circuits have not been described indetail so as not to unnecessarily obscure aspects of the embodiments ofthe invention. And, to avoid needless descriptive repetition, one ormore components or actions described in accordance with one illustrativeembodiment can be used or omitted as applicable from other illustrativeembodiments.

The embodiments below will describe various instruments and portions ofinstruments in terms of their state in three-dimensional space. As usedherein, the term “position” refers to the location of an object or aportion of an object in a three-dimensional space (e.g., three degreesof translational freedom along Cartesian X, Y, Z coordinates). As usedherein, the term “orientation” refers to the rotational placement of anobject or a portion of an object (three degrees of rotationalfreedom—e.g., roll, pitch, and yaw). As used herein, the term “pose”refers to the position of an object or a portion of an object in atleast one degree of translational freedom and to the orientation of thatobject or portion of the object in at least one degree of rotationalfreedom (up to six total degrees of freedom). As used herein, the term“shape” refers to a set of poses, positions, or orientations measuredalong an object.

Referring to FIG. 1 of the drawings, a teleoperated medical system foruse in, for example, surgical, diagnostic, therapeutic, or biopsyprocedures, is generally indicated by the reference numeral 100. Asshown in FIG. 1 , the teleoperated system 100 generally includes ateleoperational manipulator assembly 102 for operating a medicalinstrument 104 in performing various procedures on the patient P. Theassembly 102 is mounted to or near an operating table O. A masterassembly 106 allows the clinician or surgeon S to view theinterventional site and to control the slave manipulator assembly 102.

The master assembly 106 may be located at a surgeon's console which isusually located in the same room as operating table O. However, itshould be understood that the surgeon S can be located in a differentroom or a completely different building from the patient P. Masterassembly 106 generally includes one or more control devices forcontrolling the manipulator assemblies 102. The control devices mayinclude any number of a variety of input devices, such as joysticks,trackballs, data gloves, trigger-guns, hand-operated controllers, voicerecognition devices, body motion or presence sensors, or the like. Insome embodiments, the control devices will be provided with the samedegrees of freedom as the associated medical instruments 104 to providethe surgeon with telepresence, or the perception that the controldevices are integral with the instruments 104 so that the surgeon has astrong sense of directly controlling instruments 104. In otherembodiments, the control devices may have more or fewer degrees offreedom than the associated medical instruments 104 and still providethe surgeon with telepresence. In some embodiments, the control devicesare manual input devices which move with six degrees of freedom, andwhich may also include an actuatable handle for actuating instruments(for example, for closing grasping jaws, applying an electricalpotential to an electrode, delivering a medicinal treatment, or thelike).

The teleoperational assembly 102 supports the medical instrument system104 and may include a kinematic structure of one or more non-servocontrolled links (e.g., one or more links that may be manuallypositioned and locked in place, generally referred to as a set-upstructure) and a teleoperational manipulator. The teleoperationalassembly 102 includes plurality of actuators or motors that drive inputson the medical instrument system 104 in response to commands from thecontrol system (e.g., a control system 112). The motors include drivesystems that when coupled to the medical instrument system 104 mayadvance the medical instrument into a naturally or surgically createdanatomical orifice. Other motorized drive systems may move the distalend of the medical instrument in multiple degrees of freedom, which mayinclude three degrees of linear motion (e.g., linear motion along the X,Y, Z Cartesian axes) and in three degrees of rotational motion (e.g.,rotation about the X, Y, Z Cartesian axes). Additionally, the motors canbe used to actuate an articulable end effector of the instrument forgrasping tissue in the jaws of a biopsy device or the like. Motorposition sensors such as resolvers, encoders, potentiometers, and othermechanisms may provide sensor data to the teleoperational assemblydescribing the rotation and orientation of the motor shafts. Thisposition sensor data may be used to determine motion of the objectsmanipulated by the motors.

The teleoperational medical system 100 also includes a sensor system 108with one or more sub-systems for receiving information about theinstruments of the teleoperational assembly. Such sub-systems mayinclude a position sensor system (e.g., an electromagnetic (EM) sensorsystem); a shape sensor system for determining the position,orientation, speed, velocity, pose, and/or shape of the catheter tipand/or of one or more segments along a flexible body of instrumentsystem 104; and/or a visualization system for capturing images from thedistal end of the catheter system.

The visualization system (e.g., visualization system 231 of FIG. 2A) mayinclude a viewing scope assembly that records a concurrent or real-timeimage of the surgical site and provides the image to the clinician orsurgeon S. The concurrent image may be, for example, a two or threedimensional image captured by an endoscope positioned within thesurgical site. In this embodiment, the visualization system includesendoscopic components that may be integrally or removably coupled to themedical instrument 104. However in alternative embodiments, a separateendoscope, attached to a separate manipulator assembly may be used withthe medical instrument to image the surgical site. The visualizationsystem may be implemented as hardware, firmware, software or acombination thereof which interact with or are otherwise executed by oneor more computer processors, which may include the processors of acontrol system 112 (described below). The processors of the controlsystem 112 may execute instructions corresponding to processes disclosedherein.

The teleoperational medical system 100 also includes a display system110 for displaying an image or representation of the surgical site andmedical instrument system(s) 104 generated by sub-systems of the sensorsystem 108. The display 110 and the operator input system 106 may beoriented so the operator can control the medical instrument system 104and the operator input system 106 with the perception of telepresence.

The display system 110 may also display an image of the surgical siteand medical instruments captured by the visualization system. Thedisplay 110 and the control devices may be oriented such that therelative positions of the imaging device in the scope assembly and themedical instruments are similar to the relative positions of thesurgeon's eyes and hands so the operator can manipulate the medicalinstrument 104 and the hand control as if viewing the workspace insubstantially true presence. By true presence, it is meant that thepresentation of an image is a true perspective image simulating theviewpoint of an operator that is physically manipulating the instrument104.

Alternatively or additionally, the display 110 may present images of thesurgical site recorded pre-operatively or intra-operatively using imagedata from imaging technology such as, computed tomography (CT), magneticresonance imaging (MRI), fluoroscopy, thermography, ultrasound, opticalcoherence tomography (OCT), thermal imaging, impedance imaging, laserimaging, or nanotube X-ray imaging. The pre-operative or intra-operativeimage data may be presented as two-dimensional, three-dimensional, orfour-dimensional (including e.g., time based or velocity basedinformation) images or as images from models created from thepre-operative or intra-operative image data sets.

In some embodiments often for purposes of imaged guided surgicalprocedures, the display 110 may display a virtual navigational image inwhich the actual location of the medical instrument 104 is registered(i.e., dynamically referenced) with the preoperative or concurrentimages/model to present the clinician or surgeon S with a virtual imageof the internal surgical site from the viewpoint of the location of thetip of the instrument 104. An image of the tip of the instrument 104 orother graphical or alphanumeric indicators may be superimposed on thevirtual image to assist the surgeon controlling the medical instrument.Alternatively, the instrument 104 may not be visible in the virtualimage.

In other embodiments, the display 110 may display a virtual navigationalimage in which the actual location of the medical instrument isregistered with preoperative or concurrent images to present theclinician or surgeon S with a virtual image of medical instrument withinthe surgical site from an external viewpoint. An image of a portion ofthe medical instrument or other graphical or alphanumeric indicators maybe superimposed on the virtual image to assist the surgeon controllingthe instrument 104.

The teleoperational medical system 100 also includes a control system112. The control system 112 includes at least one memory and at leastone computer processor (not shown), and typically a plurality ofprocessors, for effecting control between the medical instrument system104, the operator input system 106, the sensor system 108, and thedisplay system 110. The control system 112 also includes programmedinstructions (e.g., a computer-readable medium storing the instructions)to implement some or all of the methods described in accordance withaspects disclosed herein, including instructions for providingpathological information to the display system 110. While control system112 is shown as a single block in the simplified schematic of FIG. 1 ,the system may include two or more data processing circuits with oneportion of the processing optionally being performed on or adjacent theteleoperational assembly 102, another portion of the processing beingperformed at the operator input system 106, and the like. Any of a widevariety of centralized or distributed data processing architectures maybe employed. Similarly, the programmed instructions may be implementedas a number of separate programs or subroutines, or they may beintegrated into a number of other aspects of the teleoperational systemsdescribed herein. In one embodiment, control system 112 supportswireless communication protocols such as Bluetooth, IrDA, HomeRF, IEEE802.11, DECT, and Wireless Telemetry.

In some embodiments, control system 112 may include one or more servocontrollers that receive force and/or torque feedback from the medicalinstrument system 104. Responsive to the feedback, the servo controllerstransmit signals to the operator input system 106. The servocontroller(s) may also transmit signals instructing teleoperationalassembly 102 to move the medical instrument system(s) 104 which extendinto an internal surgical site within the patient body via openings inthe body. Any suitable conventional or specialized servo controller maybe used. A servo controller may be separate from, or integrated with,teleoperational assembly 102. In some embodiments, the servo controllerand teleoperational assembly are provided as part of a teleoperationalarm cart positioned adjacent to the patient's body.

The control system 112 may further include a virtual visualizationsystem to provide navigation assistance to the medical instrumentsystem(s) 104 when used in an image-guided surgical procedure. Virtualnavigation using the virtual visualization system is based uponreference to the acquired preoperative or intraoperative dataset of theanatomical passageways. More specifically, the virtual visualizationsystem processes images of the surgical site imaged using imagingtechnology such as computerized tomography (CT), magnetic resonanceimaging (MRI), fluoroscopy, thermography, ultrasound, optical coherencetomography (OCT), thermal imaging, impedance imaging, laser imaging,nanotube X-ray imaging, or the like. Software alone or in combinationwith manual input is used to convert the recorded images into segmentedtwo dimensional or three dimensional composite representation of apartial or an entire anatomical organ or anatomical region. An imagedata set is associated with the composite representation. The compositerepresentation and the image data set describe the various locations andshapes of the passageways and their connectivity. The images used togenerate the composite representation may be recorded preoperatively orintra-operatively during a clinical procedure. In an alternativeembodiment, a virtual visualization system may use standardrepresentations (i.e., not patient specific) or hybrids of a standardrepresentation and patient specific data. The composite representationand any virtual images generated by the composite representation mayrepresent the static posture of a deformable anatomic region during oneor more phases of motion (e.g., during an inspiration/expiration cycleof a lung).

During a virtual navigation procedure, the sensor system 108 may be usedto compute an approximate location of the instrument with respect to thepatient anatomy. The location can be used to produce both macro-level(external) tracking images of the patient anatomy and virtual internalimages of the patient anatomy. Various systems for using fiber opticsensors to register and display a medical implement together withpreoperatively recorded surgical images, such as those from a virtualvisualization system, are known. For example U.S. patent applicationSer. No. 13/107,562 (filed May 13, 2011)(disclosing “Medical SystemProviding Dynamic Registration of a Model of an Anatomical Structure forImage-Guided Surgery”) which is incorporated by reference herein in itsentirety, discloses one such system.

The teleoperational medical system 100 may further include optionaloperation and support systems (not shown) such as illumination systems,steering control systems, irrigation systems, and/or suction systems. Inalternative embodiments, the teleoperational system may include morethan one teleoperational assembly and/or more than one operator inputsystem. The exact number of manipulator assemblies will depend on thesurgical procedure and the space constraints within the operating room,among other factors. The operator input systems may be collocated, orthey may be positioned in separate locations. Multiple operator inputsystems allow more than one operator to control one or more manipulatorassemblies in various combinations.

FIG. 2A illustrates a medical instrument system 200, which may be usedas the medical instrument system 104 in an image-guided medicalprocedure performed with teleoperational medical system 100.Alternatively, the medical instrument system 200 may be used fornon-teleoperational exploratory procedures or in procedures involvingtraditional manually operated medical instruments, such as endoscopy.Additionally or alternatively the medical instrument system 200 may beused to gather (i.e., measure) a set of data points corresponding tolocations with patient anatomic passageways.

The instrument system 200 includes a catheter system 202 coupled to aninstrument body 204. The catheter system 202 includes an elongatedflexible catheter body 216 having a proximal end 217 and a distal end ortip portion 218. In one embodiment, the flexible body 216 has anapproximately 3 mm outer diameter. Other flexible body outer diametersmay be larger or smaller. The catheter system 202 may optionally includea shape sensor 222 for determining the position, orientation, speed,velocity, pose, and/or shape of the catheter tip at distal end 218and/or of one or more segments 224 along the body 216. The entire lengthof the body 216, between the distal end 218 and the proximal end 217,may be effectively divided into the segments 224. If the instrumentsystem 200 is a medical instrument system 104 of a teleoperationalmedical system 100, the shape sensor 222 may be a component of thesensor system 108. If the instrument system 200 is manually operated orotherwise used for non-teleoperational procedures, the shape sensor 222may be coupled to a tracking system 230 that interrogates the shapesensor and processes the received shape data.

The shape sensor 222 may include an optical fiber aligned with theflexible catheter body 216 (e.g., provided within an interior channel(not shown) or mounted externally). In one embodiment, the optical fiberhas a diameter of approximately 200 μm. In other embodiments, thedimensions may be larger or smaller. The optical fiber of the shapesensor system 222 forms a fiber optic bend sensor for determining theshape of the catheter system 202. In one alternative, optical fibersincluding Fiber Bragg Gratings (FBGs) are used to provide strainmeasurements in structures in one or more dimensions. Various systemsand methods for monitoring the shape and relative position of an opticalfiber in three dimensions are described in U.S. patent application Ser.No. 11/180,389 (filed Jul. 13, 2005) (disclosing “Fiber optic positionand shape sensing device and method relating thereto”); U.S. patentapplication Ser. No. 12/047,056 (filed on Jul. 16, 2004) (disclosing“Fiber-optic shape and relative position sensing”); and U.S. Pat. No.6,389,187 (filed on Jun. 17, 1998) (disclosing “Optical Fibre BendSensor”), which are all incorporated by reference herein in theirentireties. Sensors in alternative embodiments may employ other suitablestrain sensing techniques, such as Rayleigh scattering, Ramanscattering, Brillouin scattering, and Fluorescence scattering. In otheralternative embodiments, the shape of the catheter may be determinedusing other techniques. For example, the history of the catheter'sdistal tip pose can be used to reconstruct the shape of the device overthe interval of time. As another example, historical pose, position, ororientation data may be stored for a known point of an instrument systemalong a cycle of alternating motion, such as breathing. This stored datamay be used to develop shape information about the catheter.Alternatively, a series of positional sensors, such as EM sensors,positioned along the catheter can be used for shape sensing.Alternatively, a history of data from a positional sensor, such as anelectromagnetic (EM) sensor, on the instrument system during a proceduremay be used to represent the shape of the instrument, particularly if ananatomical passageway is generally static. Alternatively, a wirelessdevice with position or orientation controlled by an external magneticfield may be used for shape sensing. The history of the wirelessdevice's position may be used to determine a shape for the navigatedpassageways.

The medical instrument system may, optionally, include a position sensorsystem 220. The position sensor system 220 may be a component of an EMsensor system with the sensor 220 including one or more conductive coilsthat may be subjected to an externally generated electromagnetic field.Each coil of the EM sensor system 220 then produces an inducedelectrical signal having characteristics that depend on the position andorientation of the coil relative to the externally generatedelectromagnetic field. In one embodiment, the EM sensor system may beconfigured and positioned to measure six degrees of freedom, e.g., threeposition coordinates X, Y, Z and three orientation angles indicatingpitch, yaw, and roll of a base point or five degrees of freedom. e.g.,three position coordinates X, Y, Z and two orientation angles indicatingpitch and yaw of a base point. Further description of an EM sensorsystem is provided in U.S. Pat. No. 6,380,732 (filed Aug. 11, 1999)(disclosing “Six-Degree of Freedom Tracking System Having a PassiveTransponder on the Object Being Tracked”), which is incorporated byreference herein in its entirety. In some embodiments, the shape sensormay also function as the position sensor because the shape of the sensortogether with information about the location of the base of the shapesensor (in the fixed coordinate system of the patient) allows thelocation of various points along the shape sensor, including the distaltip, to be calculated.

A tracking system 230 may include the position sensor system 220 and ashape sensor system 222 for determining the position, orientation,speed, pose, and/or shape of the distal end 218 and of one or moresegments 224 along the instrument 200. The tracking system 230 may beimplemented as hardware, firmware, software or a combination thereofwhich interact with or are otherwise executed by one or more computerprocessors, which may include the processors of the control system 112.

The flexible catheter body 216 includes a channel 221 sized and shapedto receive a medical instrument 226. Medical instruments may include,for example, image capture probes, biopsy instruments, laser ablationfibers, or other surgical, diagnostic, or therapeutic tools. Medicaltools may include end effectors having a single working member such as ascalpel, a blunt blade, an optical fiber, or an electrode. Other endeffectors may include, for example, forceps, graspers, scissors, or clipappliers. Examples of electrically activated end effectors includeelectrosurgical electrodes, transducers, sensors, and the like. Invarious embodiments, the medical tool 226 may be an image capture probethat includes a distal portion with a stereoscopic or monoscopic cameraat or near the distal end 218 of the flexible catheter body 216 forcapturing images (including video images) that are processed by avisualization system 231 for display. The image capture probe mayinclude a cable coupled to the camera for transmitting the capturedimage data. Alternatively, the image capture instrument may be afiber-optic bundle, such as a fiberscope, that couples to thevisualization system. The image capture instrument may be single ormulti-spectral, for example capturing image data in one or more of thevisible, infrared, or ultraviolet spectrums.

The medical instrument 226 may house cables, linkages, or otheractuation controls (not shown) that extend between the proximal anddistal ends of the instrument to controllably bend the distal end of theinstrument. Steerable instruments are described in detail in U.S. Pat.No. 7,316,681 (filed on Oct. 4, 2005) (disclosing “Articulated SurgicalInstrument for Performing Minimally Invasive Surgery with EnhancedDexterity and Sensitivity”) and U.S. patent application Ser. No.12/286,644 (filed Sep. 30, 2008) (disclosing “Passive Preload andCapstan Drive for Surgical Instruments”), which are incorporated byreference herein in their entireties.

The flexible catheter body 216 may also houses cables, linkages, orother steering controls (not shown) that extend between the housing 204and the distal end 218 to controllably bend the distal end 218 as shown,for example, by the broken dashed line depictions 219 of the distal end.Steerable catheters are described in detail in U.S. patent applicationSer. No. 13/274,208 (filed Oct. 14, 2011) (disclosing “Catheter withRemovable Vision Probe”), which is incorporated by reference herein inits entirety. In embodiments in which the instrument system 200 isactuated by a teleoperational assembly, the housing 204 may includedrive inputs that removably couple to and receive power from motorizeddrive elements of the teleoperational assembly. In embodiments in whichthe instrument system 200 is manually operated, the housing 204 mayinclude gripping features, manual actuators, or other components formanually controlling the motion of the instrument system. The cathetersystem may be steerable or, alternatively, the system may benon-steerable with no integrated mechanism for operator control of theinstrument bending. Also or alternatively, one or more lumens, throughwhich medical instruments can be deployed and used at a target surgicallocation, are defined in the walls of the flexible body 216.

In various embodiments, the medical instrument system 200 may include aflexible bronchial instrument, such as a bronchoscope or bronchialcatheter, for use in examination, diagnosis, biopsy, or treatment of alung. The system 200 is also suited for navigation and treatment ofother tissues, via natural or surgically created connected passageways,in any of a variety of anatomical systems, including the colon, theintestines, the kidneys, the brain, the heart, the circulatory system,and the like.

The information from the tracking system 230 may be sent to a navigationsystem 232 where it is combined with information from the visualizationsystem 231 and/or the preoperatively obtained models to provide thesurgeon or other operator with real-time position information on thedisplay system 110 for use in the control of the instrument 200. Thecontrol system 112 may utilize the position information as feedback forpositioning the instrument 200. Various systems for using fiber opticsensors to register and display a surgical instrument with surgicalimages are provided in U.S. patent application Ser. No. 13/107,562,filed May 13, 2011, disclosing. “Medical System Providing DynamicRegistration of a Model of an Anatomical Structure for Image-GuidedSurgery.” which is incorporated by reference herein in its entirety.

In the embodiment of FIG. 2A, the instrument 200 is teleoperated withinthe teleoperational medical system 100. In an alternative embodiment,the teleoperational assembly 102 may be replaced by direct operatorcontrol. In the direct operation alternative, various handles andoperator interfaces may be included for hand-held operation of theinstrument.

In alternative embodiments, the teleoperated system may include morethan one slave manipulator assembly and/or more than one masterassembly. The exact number of manipulator assemblies will depend on themedical procedure and the space constraints within the operating room,among other factors. The master assemblies may be collocated, or theymay be positioned in separate locations. Multiple master assembliesallow more than one operator to control one or more slave manipulatorassemblies in various combinations.

As shown in greater detail in FIG. 2B, medical tool(s) 228 for suchprocedures as surgery, biopsy, ablation, illumination, irrigation, orsuction can be deployed through the channel 221 of the flexible body 216and used at a target location within the anatomy. If, for example, thetool 228 is a biopsy instrument, it may be used to remove sample tissueor a sampling of cells from a target anatomical location. The medicaltool 228 may be used with an image capture probe also within theflexible body 216. Alternatively, the tool 228 may itself be the imagecapture probe. The tool 228 may be advanced from the opening of thechannel 221 to perform the procedure and then retracted back into thechannel when the procedure is complete. The medical tool 228 may beremoved from the proximal end 217 of the catheter flexible body or fromanother optional instrument port (not shown) along the flexible body.

FIG. 4 illustrates the catheter system 202 positioned within an anatomicpassageway of a patient anatomy. In this embodiment, the anatomicpassageway is an airway of a human lung. In alternative embodiments, thecatheter system 202 may be used in other passageways of an anatomy.

FIG. 4 is a flowchart illustrating a general method 450 for use in animage guided surgical procedure. At a process 452, pre-operative orintra-operative image data is obtained from imaging technology such as,computed tomography (CT), magnetic resonance imaging (MRI), fluoroscopy,thermography, ultrasound, optical coherence tomography (OCT), thermalimaging, impedance imaging, laser imaging, or nanotube X-ray imaging.The pre-operative or intra-operative image data may correspond totwo-dimensional, three-dimensional, or four-dimensional (including e.g.,time based or velocity based information) images. For example, the imagedata may represent the human lungs 201 of FIG. 3 . At a process 454,computer software alone or in combination with manual input is used toconvert the recorded images into a segmented two dimensional or threedimensional composite representation or model of a partial or an entireanatomical organ or anatomical region. The composite representation andthe image data set describe the various locations and shapes of thepassageways and their connectivity. More specifically, during thesegmentation process the images are partitioned into segments orelements (e.g., pixels or voxels) that share certain characteristics orcomputed properties such as color, density, intensity, and texture. Thissegmentation process results in a two- or three-dimensionalreconstruction that forms a model of the target anatomy based on theobtained image. To represent the model, the segmentation process maydelineate sets of voxels representing the target anatomy and then applya function, such as marching cube function, to obtain a 3D surface thatencloses the voxels This segmentation process results in a two- orthree-dimensional reconstruction that forms a model of the targetanatomy based on the obtained image. To represent the model, thesegmentation process may delineate sets of voxels representing thetarget anatomy and then apply a function, such as marching cubefunction, to obtain a 3D surface that encloses the voxels. Additionallyor alternatively, the model may include a centerline model that includesa set of interconnected line segments or points extending through thecenters of the modeled passageways. Where the model includes acenterline model including a set of interconnected line segments, thoseline segments may be converted to a cloud or set of points. Byconverting the line segments, a desired quantity of points correspondingto the interconnected line segments can be selected manually orautomatically. At a process 456, the anatomic model data is registeredto the patient anatomy prior to and/or during the course of animage-guided surgical procedure on the patient. Generally, registrationinvolves the matching of measured point to points of the model throughthe use of rigid and/or non-rigid transforms. Measured points may begenerated using landmarks in the anatomy, electromagnetic coils scannedand tracked during the procedure, or a shape sensor system. The measuredpoints may be generated for use in an iterative closest point (ICP)technique described in detail at FIG. 6 and elsewhere in thisdisclosure. Other point set registration methods may also be used inregistration processes within the scope of this disclosure.

Other registration methods for use with image-guided surgery ofteninvolve the use of technologies based on electromagnetic or impedancesensing. Metallic objects or certain electronic devices used in thesurgical environment may create disturbances that impair the quality ofthe sensed data. Other methods of registration may obstruct the clinicalworkflow. The systems and methods described below perform registrationbased upon ICP, or another point set registration algorithm, and thecalibrated movement of a point gathering instrument with a fiber opticshape sensor, thus eliminating or minimizing disruptions in the surgicalenvironment. Other registration techniques may be used to register a setof measured points to a pre-operative model or a model obtained usinganother modality. In the embodiments described below. EM sensors on thepatient and the instrument and optical tracking systems for theinstrument may be eliminated.

FIGS. 5A, 5B, and 5C illustrate some of the steps of the general method450 illustrated in FIG. 4 . FIG. 5A illustrates a segmented model 502 ofa set of anatomic passageways created from pre-operative orintra-operative imaging data. In this embodiment, the passageways areairways of a human lung. Due to naturally occurring limitations or tolimitations set by an operator, the segmented model 502 may not includeall of the passageways present within the human lungs. For example,relatively narrow and/or distal passageways of the lungs may not befully included in the segmented model 502. The segment model 502 may bea three-dimensional model, such as a mesh model, that including thewalls defining the interior lumens or passageways of the lungs.

Based on the segmented model 502, a centerline segmented model 504 maybe generated as shown in FIG. 5B. The centerline segmented model 504 mayinclude a set of three-dimensional straight lines or a set of curvedlines that correspond to the approximate center of the passagewayscontained in the segmented model 502. The higher the resolution of themodel, the more accurately the set of straight or curved lines willcorrespond to the center of the passageways. Representing the lungs withthe centerline segmented model 504 may provide a smaller set of datathat is more efficiently processed by one or more processors orprocessing cores than the data set of the segmented model 502, whichrepresents the walls of the passageways. In this way the functioning ofthe control system 112 may be improved. As shown in FIG. 5B, thecenterline segmented model 504 includes several branch points, some ofwhich are highlighted for visibility in FIG. 5B. The branch points A, B,C, D, and E are shown at each of several of the branch points. Thebranch point A may represent the point in the model at which the tracheadivides into the left and right principal bronchi. The right principalbronchus may be identified in the centerline segment model 504 as beinglocated between branch points A and B. Similarly, secondary bronchi areidentified by the branch points B and C and between the branch points Band E. Another generation may be defined between branch points C and D.Each of these generations may be associated with a representation of thediameter of the lumen of the corresponding passageway. In someembodiments, the centerline model 504 may include an average diametervalue of each segmented generation. The average diameter value may be apatient-specific value or a more general value derived from multiplepatients.

In some embodiments, the centerline segmented model 504 is representedin data as a cloud, set, or collection of points in three-dimensionalspace, rather than as continuous lines. FIG. 5C illustrates thecenterline segmented model 504 as a set of points 506. In data, each ofthe points of the set of model points may include coordinates such as aset of X_(M), Y_(M), and Z_(M), coordinates, or other coordinates thatidentify the location of each point in the three-dimensional space. Insome embodiments, each of the points may include a generation identifierthat identifies which passageway generation the points are associatedwith and/or a diameter or radius value associated with that portion ofthe centerline segmented model 504. In some embodiments, informationdescribing the radius or diameter associated with a given point may beprovided as part of a separate data set.

After the centerline segmented model 504 is generated and stored in dataas the set of points 506 shown in FIG. 5C, the centerline segmentedmodel 504 may be retrieved from data storage for use in an image-guidedsurgical procedure. In order to use the centerline segmented model 504in the image-guided surgical procedure, the model 504 may be registeredto associate the modeled passageways in the model 504 with the patient'sactual anatomy as present in a surgical environment. Use of the model504 in point set registration includes using the set of points 506 fromthe model 504.

FIGS. 6A and 6B illustrate an exemplary surgical environment 600according to some embodiments, with a surgical coordinate system X_(S),Y_(S), Z_(S), in which a patient P is positioned on a platform 602. Thepatient P may be stationary within the surgical environment in the sensethat gross patient movement is limited by sedation, restraint, or othermeans. Cyclic anatomic motion including respiration and cardiac motionof the patient P continues. Within the surgical environment 600, a pointgathering instrument 604 is coupled to an instrument carriage 606. Invarious embodiments, the point gathering instrument 604 may use EMsensors, shape-sensors, and/or other sensor modalities. The instrumentcarriage 606 is mounted to an insertion stage 608 fixed within thesurgical environment 600. Alternatively, the insertion stage 608 may bemovable but have a known location (e.g., via a tracking sensor or othertracking device) within the surgical coordinate system. The instrumentcarriage 606 may be a component of a teleoperational manipulatorassembly (e.g., assembly 102) that couples to the instrument 604 tocontrol insertion motion (i.e. motion in an X_(S) direction) and,optionally, motion of a distal end of the instrument in multipledirections including yaw, pitch, and roll. The instrument carriage 606or the insertion stage 608 may include servomotors (not shown) thatcontrol motion of the instrument carriage along the insertion stage.

The point gathering instrument 604 may include a flexible catheter 610coupled to a proximal rigid instrument body 612. The rigid instrumentbody 612 is coupled and fixed relative to the instrument carriage 606.In the illustrated embodiment, an optical fiber shape sensor 614 isfixed at a proximal reference point 616 on the rigid instrument body612. In this embodiment, the reference point 616 is located outside ofthe patient anatomic passageways, but in alternative embodiments, thereference point may travel within the patient. In an alternativeembodiment, the point 616 of the sensor 614 may be movable along thebody 612 but the location of the point may be known (e.g., via atracking sensor or other tracking device). The shape sensor 614 measuresa shape from the reference point 616 to another point such as the distalend 618 of the catheter 610. The point gathering instrument 604 may besubstantially similar to the medical instrument system 200.

A position measuring device 620 provides information about the positionof the rigid instrument body 612 as it moves on the insertion stage 608along an insertion axis A. The position measuring device 620 may includeresolvers, encoders, potentiometers, and other mechanisms that determinethe rotation and orientation of the motor shafts controlling the motionof the instrument carriage 606 and consequently the motion of therigidly attached instrument body 612. In this embodiment, the insertionstage 608 is linear, but in alternative embodiments it may be curved orhave a combination of curved and linear sections. Optionally, the lineartrack may be collapsible as described, for example, in U.S. ProvisionalPatent Application No. 62/029,917 (filed Jul. 28, 2014)(disclosing“Guide Apparatus For Delivery Of A Flexible Instrument And Methods OfUse”) which is incorporated by reference herein in its entirety. FIG. 6shows the instrument body 612 and carriage 606 in a retracted positionalong the insertion stage 608. In this retracted position, the proximalpoint 616 is at a position L₀ on the axis A. In this position along theinsertion stage 608 an Xs component of the location of the point 616 maybe set to a zero or original value. With this retracted position of theinstrument body 612 and carriage 606, the distal end 618 of the cathetermay be positioned just inside an entry orifice of the patient P. Also inthis position, the position measuring device may be set to a zero ororiginal value (e.g. I=0). In FIG. 7 , the instrument body 612 and thecarriage 606 have advanced along the linear track of the insertion stage608 and the distal end of the catheter 610 has advanced into the patientP. In this advanced position, the proximal point 616 is at a position L₁on the axis A.

Embodiments of the point gathering instrument 604 may collect measuredpoints using any number of modalities, including EM sensing andshape-sensing. As the measurement points are collected from within thepassageways of a patient, the points are stored in a data storagedevice, such as a memory. The set of measured points may be stored in adatabase that includes at least some, but may include all, of themeasured points obtained during the procedure or immediately before theprocedure. As stored in memory, each of the points may be represented bydata comprising coordinates of the point, a timestamp, and a relativesensor position or individual sensor ID (when multiple sensorsdistributed along a length of the point gathering instrument 604 areused to determine the location of several points simultaneously). Insome embodiments, data representing each point may also include arespiratory phase marker that indicates the respiratory phase of thepatient in which the point was collected.

FIG. 8 is a flowchart illustrating a method 500 used to provide guidanceto a clinician in an image-guided surgical procedure on the patient P inthe surgical environment 600, according to an embodiment of the presentdisclosure. The method 500 is illustrated in FIG. 8 as a set of blocks,steps, operations, or processes. Not all of the illustrated, enumeratedoperations may be performed in all embodiments of the method 500.Additionally, some additional operations that are not expresslyillustrated in FIG. 8 may be included before, after, in between, or aspart of the enumerated processes. Some embodiments of the method 500include instructions corresponded to the processes of the method 500 asstored in a memory. These instructions may be executed by a processorlike a processor of the control system 112.

Thus, some embodiments of the method 500 may begin at a process 502, inwhich a calibration procedure is performed to calibrate, with a positionmeasuring device like the point gathering instrument 604 or anothersuitable device, a relative position and/or orientation of a sensorreference point along an insertion path. For example, the pointgathering instrument 604 of FIGS. 6 and 7 may be used to determine aposition and orientation of the point 616 as the carriage 606 moves froma retracted position with the point 616 at location L₀ to an advancedposition with the point 616 at the location L₁. The calibrationprocedure determines the direction of the movement of the point 616 foreach change in the position measuring device 620. In this embodiment,where the insertion stage 608 restricts movement of the carriage 606 toa linear path, the calibration procedure determines the direction of thestraight line. One such calibration method is to measure the differencein position between two points along the straight section of thecatheter, the direction of that difference vector is the direction ofthe insertion axis. An alternative method is to constrain a known pointof the catheter (e.g. the tip) in a fixed location and to measure therelative position of point 616 with respect to that known fixed point asthe backend traverses along the insertion axis, and then to fit adirection vector to this collection of measured points. From the slopeof the insertion stage track, the position and orientation of the point616 in the surgical environment 600 may be determined for everycorresponding measurement of the position measuring device 620. In analternative embodiment, if the insertion stage has a curved or otherwisenon-linear shape, the calibration procedure may determine the non-linearshape so that for every measurement of the position device, the positionand orientation of the point 616 in the surgical environment may bedetermined. For example, the distal tip of the catheter may be held in afixed position while the instrument body is routed along the non-linearinsertion stage. The position and orientation data collected by theshape sensor from the fixed point 616 is correlated with the positionmeasuring device data as the instrument body is routed along theinsertion stage, thus calibrating movement of the point 616 along theaxis A of the insertion stage 608.

At a process 504, the distal end 618 of the catheter traverses thepatient P's anatomical passageways (e.g., airways of the patient'slungs) recording, via data from the shape sensor 614, location data forthe distal end of the catheter and/or other points along the shape ofthe shape sensor. This location data may include, or be processed toobtain, a set of measured points as described herein. More specifically,the movement of the distal tip of the catheter 610 is controlled viateleoperational, manual, or automated control (e.g., via master assembly106) to survey a portion of the anatomical passageways. For example,teleoperational control signals may cause the carriage 606 to move alongthe axis A, causing the distal tip 618 of the catheter to advance orretract within the anatomical passageways. Also or alternatively,teleoperational control signals may cause actuation of control membersextending within the surgical instrument to move the distal tip 618 in arange of movements including yaw, pitch, and roll. As the catheter ismoved within the plurality of passageways, shape sensor data is gatheredfor multiple locations of the distal tip. In some embodiments, thecatheter may extend up to approximately three inches into the variouspassageways. In some embodiments, the catheter may be extended throughor into approximately three branched generations on each side of thelung. The number of generations accessible with the catheter 610 mayincrease as the diameter of the flexible catheter 610 decreases and/orthe flexibility of the flexible catheter increases.

With reference to FIG. 9 , shape sensor data is gathered for a set ofmeasured data points D. The measured data points may be store in memoryas data sets or point pools with coordinates, timestamps, sensor IDs,respiration phase information, or the like for each gathered point. Thiscollected set of spatial information provided by data points D from theshape sensor or other point collection device may be gathered as thedistal end 618 of the catheter 610 is moved to a plurality of locationswithin the surgical space 600 (i.e., the teleoperational manipulatorspace). The location of a given collected data point D_(X) in thesurgical environment space 600 is determined by combining informationfrom the position measuring device 620 when the distal end of thecatheter is located at the point D_(X) with the shape data from theshape sensor when the distal end of the catheter is located at the pointD_(X). Points may also be collected along the length of the catheter. Inboth cases, the data from the position measuring device 620 and thecalibrated path of the fixed sensor point 616 provides the position ofthe sensor point 616 in the patient surgical environment 600 when thedistal end 618 of the catheter is at the point D_(X). For example,encoder data from one or more motors controlling movement of thecarriage 606 along the track 608 and the calibration data from themovement of the carriage along the track provides the position of thesensor point 616 in the surgical environment 600 when the distal end ofthe catheter is at the point D_(X). The shape sensor provides the shapeof the instrument between the fixed sensor point 616 and the distal end618. Thus, the location of the point D_(X) (where the distal end 618 islocated) in the surgical environment space 600 can be determined fromthe calibrated position measuring data and the shape sensor datarecorded when the distal end is at point D_(X). The location in thesurgical environment 600 coordinate space for all of the data points Din the set of gathered data points (i.e. calibrated position of theproximal point 616 together combined with the shape sensor data for thelocation of the distal end 618 relative to the point 616) is a referenceset of spatial information for the instrument that can be registeredwith anatomic model information.

Referring again to FIG. 8 , at a process 506, one or more of thegathered data points D may correspond to landmark locations in thepatient anatomy. In some embodiments, the gathered data points D thatcorrespond to landmarks may be used to seed a registration process, suchas an ICP process. This subset of gathered data points D that correspondto one or more landmarks may be referred to as seed points. The datarepresenting the subset of gathered data points D that correspond tolandmarks may include a landmark indicator when stored in memory. Withreference to FIG. 11 , a set of anatomical passageways 700 include maincarinas C1, C2, C3 where the passageways 700 fork. A data point D can begathered for the location of each carina by moving the distal end of thecatheter to the respective carina locations. For example, a data pointD_(L1) can be gathered at the carina C₁. A data point D_(L2) can begathered at the carina C₂. A data point D_(L3) can be gathered at thecarina C₃. The carinas or other suitable landmarks can be located in thepatient surgical environment 600 as described above for point D_(X). Theprocess 506 is optional and may be omitted if alternative seedingtechniques are used.

Referring again to FIG. 8 , at a process 508 anatomical modelinformation is received. The anatomic model information may be thesegmented centerline model 504 as described in FIG. 5C. Referring againto FIG. 9 , the anatomical model information may be represented as acenterline model 550 of branched anatomic passageways. In someembodiments, the model may include one or more landmark points to matchto the seed points D_(L1), D_(L2), and D_(L3). These points included inthe model to match to the seed points D_(L1), D_(L2) and D_(L3) may notbe centerline points in some embodiments, but may be included in thecenterline model 550 to facilitate seeding of a subsequent registrationprocess. In some embodiments, the centerline model 550 may include moremodel landmark points than M_(L1), M_(L2), and M_(L3).

Referring again to FIG. 8 , at a process 510 registration of theanatomical model information 550 with the set of gathered data points Dfrom the surgical environment 600 is performed. Registration may beaccomplished using a point set registration algorithm such as aniterative cloud point (ICP) technique as described in processes 512-520,or by implementation of another registration algorithm. At process 512,the ICP registration is seeded with known information about thedisplacement and orientation relationship between the patient surgicalenvironment and the anatomical model. In this embodiment (FIG. 11 ), forexample, the carina landmarks C₁, C₂. C₃ are identified in theanatomical model information as points M_(L1), M_(L2), M_(L3). Inalternative embodiments, the anatomical model information may berepresented in other ways, e.g. as centerline segments or axes of a 3Dmesh model. Or alternatively, the model may be expressed as a volumeconstructed from 3D shapes such as cylinders or as a 3D image. Therecorded landmark data points D_(L1), D_(L2), D_(L3) from the patientsurgical environment are each matched to a corresponding model pointsM_(L1), M_(L2), M_(L3), (i.e., D_(L1) matches to M_(L1), etc.) With thepoints matched, an initial transform (e.g., change in position and/ororientation) between landmark data points D_(L1), D_(L2), D_(L3) andmodel points M_(L1), M_(L2), M_(L3) is determined. The transform may bea rigid transform in which all landmark data points are transformed bythe same change in position and orientation or may be a non-rigidtransform in which the landmark datapoints are transformed by differentchanges in position and orientation. The transform determined with thelandmark data points D_(L1), D_(L2), D_(L3) may applied to all of thegathered data points D. This seeding process, based on a few landmarkpoints, provides an initial coarse registration of the gathered datapoints D to the anatomical model.

An alternative method to obtain an initial coarse registration is to useapproximately known information about the teleoperational manipulatorassembly and the patient location. The teleoperational manipulatorassembly may be instrumented with encoders or other sensors that measurethe relative pose of the insertion track with respect to gravity. Thisinformation may be combined with patient orientation assumptions, e.g.,the patient is lying on his back, and the assumption that the insertiontrack is placed at the patient's mouth. The combined information maythus also provide an approximate relative orientation and position ofthe instrument with respect to the patient and be sufficient as seedingregistration to proceed with full registration.

At a process 514, with the initial coarse registration performed, theset of gathered data points D is matched to the anatomical modelinformation 550 (FIG. 9 ). In this embodiment, the anatomical modelinformation is a set of points along the centerlines of the anatomicmodel. The ICP algorithm identifies matches between closest points inthe gathered data points D and in the set of anatomic model points. Invarious alternatives, matching may be accomplished by using brute forcetechniques, KD tree techniques, maximum distance threshold calculations,maximum angle threshold calculations, model centerline points, modelmesh points, and/or model volume points. In another embodiment, matchingis not required at all, but rather each gathered point is mapped to anearest point on or within the model using some explicit mappingfunction or by using a look-up-table. The matching or mapping betweengathered points and model points may further be informed by additionalcriteria such as the insertion depth, respiratory phase, motor torque,velocity, etc.

At a process 516, the motion needed to move the set of gathered datapoints D to the position and orientation of the matched anatomic modelpoints is determined. More specifically, an overall offset in positionand orientation is determined for the set of gathered data points D.FIG. 9 , for example, illustrates an initial offset of approximately 20°in orientation and 40 mm in displacement between the gathered datapoints D and the anatomical model information 550.

At a process 518, the set of gathered data points D are transformedusing a rigid or non-rigid transformation that applies the computedoffset in displacement and orientation to move each point in the set ofgathered data points D. As shown in FIG. 10 , the set of gathered datapoints D is transformed to converge with the model points 550.

At a process 520, the convergence of the gathered data points D and thematched anatomic model points 550 are evaluated. In other words, errorfactors for orientation and displacement may be determined for eachmatched point set. If the error factors in aggregate are greater than athreshold value, additional iterations of processes 514-520 may berepeated until the overall position and orientation error factors fallsbelow the threshold value.

The registration process 510 may recomputed multiple times during asurgical procedure (e.g. approximately twice per hour, but may be moreor less frequently) in response to deformation of the passageways causedby cyclic anatomical motion, instrument forces, or other changes in thepatient environment.

After the anatomic model and the patient environment are registered, animage guided surgical procedure may, optionally, be performed. Referringagain to FIG. 8 , at process 522, during a surgical procedure, a currentlocation of a surgical instrument in the surgical environment isdetermined. More specifically, the data from the position measuringdevice 620 and the calibrated path of the fixed sensor point 616provides the position of the sensor point 616 in the patient surgicalenvironment 600 when the catheter is in a current location. The shapesensor provides the shape of the instrument between the fixed sensorpoint 616 and the distal end 618. Thus, the current location of thecatheter 210 and particularly the distal end 618 of the catheter in thesurgical environment space 600 can be determined from the calibratedposition measuring data and the shape sensor data.

At process 524, the previously determined registration transforms areapplied to the current instrument position and shape data to localizethe current instrument to the anatomic model. For example, the currentposition and orientation for the distal end of the instrument, datapoint D_(current) is transformed using the one or more transformiterations determined at process 510. Thus, the data point D_(current)in the surgical environment 600 is transformed to the anatomic modelspace. In an alternative embodiment, the anatomical model may instead beregistered to the surgical environment in which the catheter positiondata is gathered.

At process 526, optionally, the localized instrument may be displayedwith the anatomic model to assist the clinician in an image guidedsurgery. FIG. 12 illustrates a display system 800 displaying a renderingof anatomical passageways 802 of a human lung 804 based upon anatomicalmodel information. With the surgical environment space registered to themodel space as described above in FIG. 8 , the current shape of thecatheter 610 and the location of the distal end 618 may be located anddisplayed concurrently with the rendering of the passageways 802.

Although the systems and methods of this disclosure have been describedfor use in the connected bronchial passageways of the lung, they arealso suited for navigation and treatment of other tissues, via naturalor surgically created connected passageways, in any of a variety ofanatomical systems including the colon, the intestines, the kidneys, thebrain, the heart, the circulatory system, or the like.

One or more elements in embodiments of the invention may be implementedin software to execute on a processor of a computer system such ascontrol system 112. When implemented in software, the elements of theembodiments of the invention are essentially the code segments toperform the necessary tasks. The program or code segments can be storedin a processor readable storage medium or device that may have beendownloaded by way of a computer data signal embodied in a carrier waveover a transmission medium or a communication link. The processorreadable storage device may include any medium that can storeinformation including an optical medium, semiconductor medium, andmagnetic medium. Processor readable storage device examples include anelectronic circuit; a semiconductor device, a semiconductor memorydevice, a read only memory (ROM), a flash memory, an erasableprogrammable read only memory (EPROM); a floppy diskette, a CD-ROM, anoptical disk, a hard disk, or other storage device. The code segmentsmay be downloaded via computer networks such as the Internet, Intranet,etc.

Note that the processes and displays presented may not inherently berelated to any particular computer or other apparatus. The requiredstructure for a variety of these systems will appear as elements in theclaims. In addition, the embodiments of the invention are not describedwith reference to any particular programming language. It will beappreciated that a variety of programming languages may be used toimplement the teachings of the invention as described herein.

While certain exemplary embodiments of the invention have been describedand shown in the accompanying drawings, it is to be understood that suchembodiments are merely illustrative of and not restrictive on the broadinvention, and that the embodiments of the invention not be limited tothe specific constructions and arrangements shown and described, sincevarious other modifications may occur to those ordinarily skilled in theart.

What is claimed is:
 1. A system comprising: a manipulator configured tomove a medical instrument in a medical environment; and a processingunit operatively coupled to the manipulator, wherein the processing unitis configured to: receive, from a position sensor system, a collectedset of spatial information for a distal portion of the medicalinstrument, the collected set of spatial information collected at aplurality of locations within a set of anatomic passageways, wherein thecollected set of spatial information is measured as a rigid instrumentbody disposed at a proximal portion of the medical instrument is movedin an insertion or retraction direction by the manipulator; receive,from a position measuring device of the manipulator, a set of positioninformation related to a position of the rigid instrument body when thedistal portion of the medical instrument is at each of the plurality oflocations as the medical instrument is moved in the insertion orretraction direction, wherein the set of position information is in anenvironment coordinate space; based at least in part on the set ofposition information, determine a subset of the collected set of spatialinformation for the distal portion of the medical instrument relative tothe environment coordinate space; and based on the subset of thecollected set of spatial information, determine an initial transform forregistering the collected set of spatial information with a set ofanatomical model information in a model coordinate space.
 2. The systemof claim 1, wherein the manipulator comprises an instrument carriagecouplable to the rigid instrument body of the medical instrument tocontrol movement of the medical instrument in the insertion orretraction direction.
 3. The system of claim 2, wherein the positionmeasuring device is configured to determine an orientation of at leastone motor shaft controlling motion of the instrument carriage.
 4. Thesystem of claim 1, wherein the position measuring device comprises atleast one of a motor position sensor, a resolver, an encoder, or apotentiometer.
 5. The system of claim 1 wherein the position sensorsystem comprises a fiber optic shape sensor extending between the distalportion of the medical instrument and the rigid instrument body.
 6. Thesystem of claim 5 wherein the fiber optic shape sensor is fixed at therigid instrument body.
 7. The system of claim 1 wherein the positionsensor system comprises at least one electromagnetic sensor disposed inthe distal portion of the medical instrument.
 8. The system of claim 1wherein the processing unit is further configured to receive commandsfrom a control device to move the medical instrument through theplurality of locations within the set of anatomic passageways.
 9. Thesystem of claim 1 wherein the set of anatomical model information isgenerated from a set of pre-operative anatomic images.
 10. The system ofclaim 1 wherein the processing unit is configured to: register thecollected set of spatial information with the set of anatomical modelinformation.
 11. The system of claim 10 wherein registering thecollected set of spatial information with the set of anatomical modelinformation includes applying the initial transform to the collected setof spatial information.
 12. The system of claim 1, wherein the subset ofthe collected set of spatial information for the distal portion of themedical instrument includes at least one data point corresponding to amain carina of the set of anatomic passageways.
 13. A system comprising:an instrument comprising: a rigid instrument body; a flexible catheterextending from the rigid instrument body; and a position sensor systemconfigured to collect a collected set of spatial information for adistal portion of the flexible catheter at a plurality of locationswithin a set of anatomic passageways; a manipulator comprising: aninstrument carriage configured to receive the rigid instrument body andmove the rigid instrument body in a medical environment; and a positionmeasuring device configured to determine a set of position informationfor the instrument carriage in an environment coordinate space as therigid instrument body is moved in an insertion or retraction direction;and a processing unit operatively coupled to the manipulator andconfigured to: receive the collected set of spatial information; receivethe set of position information; based at least in part on the set ofposition information, determine a subset of the collected set of spatialinformation; and based on the subset of the collected set of spatialinformation, determine an initial transform for registering thecollected set of spatial information with a set of anatomical modelinformation in a model coordinate space.
 14. The system of claim 13,wherein the position measuring device is configured to determine anorientation of at least one motor shaft controlling motion of theinstrument carriage.
 15. The system of claim 13, wherein the positionmeasuring device comprises at least one of a motor position sensor, aresolver, an encoder, or a potentiometer.
 16. The system of claim 13wherein the position sensor system comprises a fiber optic shape sensorextending between the distal portion of the flexible catheter and therigid instrument body.
 17. The system of claim 13 wherein the positionsensor system comprises at least one electromagnetic sensor disposed inthe distal portion of the flexible catheter.
 18. The system of claim 13wherein the processing unit is further configured to receive commandsfrom a control device to move the instrument through the plurality oflocations within the set of anatomic passageways.
 19. The system ofclaim 13 wherein the processing unit is configured to: register thecollected set of spatial information with the set of anatomical modelinformation.
 20. The system of claim 19 wherein registering thecollected set of spatial information with the set of anatomical modelinformation includes applying the initial transform to the collected setof spatial information.